A5062451983- Geological and Geophysical Studies
- Paleontology and Stratigraphy of Fossils
- Geological formations and processes
- Hydrocarbon exploration and reservoir analysis
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Geochemistry and Elemental Analysis
- Paleontology and Evolutionary Biology
- Geochemistry and Geologic Mapping
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Coral and Marine Ecosystems Studies
- Marine and coastal plant biology
- Plant Diversity and Evolution
- Geochemistry and Geochronology of Asian Mineral Deposits
- Reservoir Engineering and Simulation Methods
- Groundwater and Isotope Geochemistry
- Food Industry and Aquatic Biology
- Geological and Tectonic Studies in Latin America
- Coastal and Marine Management
- Seismic Imaging and Inversion Techniques
- Marine Biology and Ecology Research
- Geological Modeling and Analysis
- Water Quality Monitoring Technologies
- Remote Sensing and Land Use
Geological Survey of Alabama
2017-2023
University of Alabama
2017-2023
The University of Arizona Global Campus
2015-2020
Shell (United States)
2011-2020
Shell (Japan)
2014
Shell (Netherlands)
2012-2013
University of Kansas
2007
Isolated carbonate buildups (ICBs) are commonly attractive exploration targets. However, identifying ICBs based only on seismic data can be difficult for a variety of reasons. These include poor-quality two-dimensional and basic similarity between other features such as volcanoes, erosional remnants, tilted fault blocks. To address these difficulties develop reliable methods to identify ICBs, 234 images were analyzed. The included proven features, folds, basement highs, which may appear...
Research Article| July 01, 2015 ENVIRONMENTAL CONTROLS ON THE GENESIS OF MARINE MICROBIALITES AND DISSOLUTION SURFACE ASSOCIATED WITH END-PERMIAN MASS EXTINCTION: NEW SECTIONS OBSERVATIONS FROM NANPANJIANG BASIN, SOUTH CHINA DANIEL J. LEHRMANN; LEHRMANN 1Geoscience Department, Trinity University, San Antonio, Texas 78212, USA e-mail: dlehrmann@trinity.edu Search for other works by this author on: GSW Google Scholar JOHN M. BENTZ; BENTZ TANNER WOOD; WOOD ALEXA GOERS; GOERS RYAN DHILLON;...
The Nanpanjiang Basin of south China contains four exceptionally well-exposed, isolated Triassic carbonate platforms. Detailed mapping two-dimensional transects and description stratigraphic sections allow the reconstruction facies architecture, sequence stratigraphy, evolution Biostratigraphy, magnetic-susceptibility profiles, volcanic-ash horizons chronostratigraphic correlation and, thus, a basinwide evaluation mechanisms controlling platform evolution. A comparison architecture...
Lower Triassic platforms in the Nanpanjiang Basin contain extensive oolites. Interior oolites are stacked meter-scale cycles arranged into larger coarsening-upward sequences. Oolites thicken toward margins to include grainstones up 50 m (164 ft) thick and giant ooids (up 1 cm [0.4 in.]) composite coated grains. Cross-bedding, ripples, abraded indicate deposition high-energy shoals. Apparent layer-cake correlation across interiors indicates amalgamation of Thinner interior lenses represent...
Abstract The Nanpanjiang Basin occurs in a key position for resolving controversies of basin tectonics and patterns plate assembly at the junction between south China Southeast Asian plates. Paleocurrent measurements indicate that siliciclastic turbidites were sourced by Precambrian Jiangnan uplift to northeast, Yunkai southeast Triassic Songma suture south. Detrital zircon geochronology reveals Archean (2500 Ma), Paleoproterozoic (1800–1900 Neoproterozoic (900–1000 Ma) Paleozoic (420–460...
Abstract Lower Triassic limestones contain giant ooids (>2 mm) along with other precipitated carbonate textures more typical of Precambrian strata. These features appear to have resulted from changes in seawater chemistry associated the end-Permian mass extinction, but quantifying Early has remained challenging. To constrain saturation state, dissolved inorganic carbon, alkalinity, and pH, we applied a physicochemical model ooid formation constrained by new size data on south China,...
Abstract Regional and detailed seismic stratigraphic analyses of Early Cretaceous (Aptian) presalt carbonate sections from offshore Brazil reveal the complex architecture late- post-rift lacustrine systems. The lateral vertical distribution calibrated facies within this framework highlights evolution through time system bathymetry host basin. Despite simple, largely abiotic microbial components, accumulations formed geometries that closely resemble those observed marine systems, suggesting a...
Abstract The Yangtze Platform drowned and was buried by pelagic facies siliciclastic turbidites in western Guizhou Province during the Late Triassic, Carnian. uppermost platform of Ladinian Yangliujing Fm. consists peritidal cyclic carbonate. margin Longtou consist grainstone lenses coral–Tubiphytes algal boundstone indicating high-energy shoals patch reefs. drowning horizon is laterally variable; it either a sharp surface or gradational shift to dark, nodular-bedded lime mudstone wackestone...
Abstract Sector‐collapse structures ranging up to 27 km wide with 7.7 bankward erosion (scalloped margins) and linear escarpments occur along the east‐north‐east‐trending, south‐facing margins of Yangtze Platform Great Bank Guizhou. Exposure one on rotated limb a syncline displays geometry in profile view. Declivities range from 65° 90° upper wall decrease asymptotically toe. Catastrophic collapses both platforms occurred during late Ladinian as constrained by ages strata truncated...
Abstract Carbonate platforms spanning intervals of global change provide an opportunity to identify causal links between the evolution marine environment and depositional architecture. This study investigates controls on platform geometry across Palaeozoic Mesozoic transition yields new stratigraphic palaeoenvironmental constraints Great Bank Guizhou, a latest Permian earliest Late Triassic isolated carbonate in Nanpanjiang Basin south China. Reconstruction architecture was achieved by...
The dolomites of the Jurassic Smackover Formation have been subject considerable study in past decades, yet there is little agreement on processes that produced these dolomites. Proposed mechanisms include: 1) reflux, 2) penecontemporaneous supratidal [sabkha], 3) seawater-meteoric mixing, 4) evaporative-reflux meteoric 5) confined aquifer 6) thermal convection, 7) seawater-seepage, and 8) evaporated seawater seepage. This investigates from Florida to Mississippi northern rim Gulf Mexico. It...
Abstract The upper Cambrian Wilberns Formation in central Texas records deposition on a low‐gradient shelf within mixed carbonate–siliciclastic tidal‐flat system that changes offshore to subtidal and open‐marine oolitic skeletal shoals with large microbial mounds. Siliciclastic sediment is interpreted have been delivered the tidal flat by aeolian processes because of narrow range grain size paucity clay. Tidal influence dominant as evidenced reversing currents desiccation flat, megaripples...
Abstract The end‐Permian extinction and its aftermath altered carbonate factories globally for millions of years, but impact on platform geometries remains poorly understood. Here, the evolution in architecture composition two exceptionally exposed platforms Nanpanjiang Basin are constrained compared with geochemical proxies to evaluate controls geometries. Geochemical indicate elevated siliciclastic nutrient fluxes basal Triassic, at Induan—Olenekian boundary uppermost Olenekian. Cerium/Ce*...
The Late Permian to Triassic Great Bank of Guizhou (GBG) in southwest China is one the few isolated carbonate platforms world that exposes an essentially complete record initiation, development, and drowning across multiple platform-to-basin transects. platform exceptionally exposed cross section at surface by a faulted syncline rotated strata dip angle approximately 65°. Platform development spanned end-Permian extinction recovery marks transition from Paleozoic Mesozoic styles sediment...
We appreciate Kershaw et al.'s comment and continued interest in our Permian–Triassic research the Nanpanjiang Basin. al. on aspects of recent study that contradict results from Collin (2009). Specifically their comments center around two questions: (1) whether truncation surface at base microbialite shows evidence for subaerial exposure, (2) data support model genesis microbialites by upwelling anoxic, alkaline waters with elevated carbonate saturation bacterial sulfate reduction (Kershaw...